Datasheet

74AHC_AHCT257_2 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 02 — 9 May 2008 8 of 16
NXP Semiconductors
74AHC257; 74AHCT257
Quad 2-input multiplexer; 3-state
10. Dynamic characteristics
Table 7. Dynamic characteristics
Voltages are referenced to GND (ground = 0 V); for test circuit see Figure 8.
Symbol Parameter Conditions 25 °C −40 °C to +85 °C −40 °C to +125 °C Unit
Min Typ
[1]
Max Min Max Min Max
74AHC257
t
pd
propagation
delay
nI0, nI1 to nY; see Figure 6
[2]
V
CC
= 3.0 V to 3.6 V
C
L
= 15 pF - 4.2 9.3 1.0 11.0 1.0 12.0 ns
C
L
= 50 pF - 6.0 12.8 1.0 14.5 1.0 16.0 ns
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 2.9 5.9 1.0 7.0 1.0 7.5 ns
C
L
= 50 pF - 4.2 7.9 1.0 9.0 1.0 11.5 ns
S to nY; see
Figure 6
[2]
V
CC
= 3.0 V to 3.6 V
C
L
= 15 pF - 5.2 11.0 1.0 13.0 1.0 14.0 ns
C
L
= 50 pF - 7.4 14.5 1.0 16.5 1.0 18.5 ns
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 3.5 6.8 1.0 8.0 1.0 8.5 ns
C
L
= 50 pF - 5.0 8.8 1.0 10.0 1.0 12.5 ns
t
en
enable time OE to nY; see Figure 7
[3]
V
CC
= 3.0 V to 3.6 V
C
L
= 15 pF - 4.5 10.5 1.0 12.5 1.0 13.5 ns
C
L
= 50 pF - 6.4 14.0 1.0 16.0 1.0 17.5 ns
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 3.2 6.8 1.0 8.0 1.0 8.5 ns
C
L
= 50 pF - 4.5 8.8 1.0 10.0 1.0 12.5 ns
t
dis
disable time OE to nY; see Figure 7
[4]
V
CC
= 3.0 V to 3.6 V
C
L
= 15 pF - 5.1 9.5 1.0 11.0 1.0 11.5 ns
C
L
= 50 pF - 7.2 12.0 1.0 13.5 1.0 14.5 ns
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 3.4 6.5 1.0 7.0 1.0 8.5 ns
C
L
= 50 pF - 4.9 7.9 1.0 9.0 1.0 9.5 ns
C
PD
power
dissipation
capacitance
f
i
= 1 MHz; V
I
= GND to V
CC
[5]
4 outputs switching via
input S
-45- - - - -pF
1 output switching via
input I
-15- - - - -pF